1. Field of the Invention
The invention relates to a method for producing a male terminal fitting that has a tab.
2. Description of the Related Art
A known tab for a male terminal fitting is shown in Japanese Patent Publication No. 3-291872 and is identified by the numeral 1 in FIG. 8 herein. The tab 1 has a planar base 2 and a tapered tip 3 at the leading end of the base 2 to facilitate insertion into a cavity of a connector, a mating female terminal fitting or the like.
The tab 1 is formed from a metallic plate that is stamped by a press into an elongated blank or development, as shown in FIG. 9. The development is divided into three sections along the widthwise direction to define a center section 1A and left and right sections 1B. The leading ends of the sections 1A, 1B define trapezoidal cut surfaces 4A, 4B that taper toward their ends.
The tab 1 is formed by folding the left and right sections 1B along longitudinal fold lines and onto the upper surface of the center section 1A. Hence the tab 1 has a thickness that is twice the thickness of the metallic plate. At this time, the cut surfaces 4A, 4B of the center section 1A and the left and right sections 1B are aligned to form the tapered trapezoidal tip 3.
The tip 3 is pressed from above and below to form slanted surfaces 5 on its upper and lower surfaces and to become tapered also in side view.
The tip 3 of the tab 1 is stamped out of the metallic plate by the press, as described above. Thus, sharp edges 6 are formed around the cut surfaces 4A, 4B. As a result, the edges 6 may damage the wall surfaces of a cavity of a connector during insertion of the male terminal fitting into the cavity. The edges 6 may damage a waterproof rubber plug as the tip 3 is introduced through a hole of the rubber plug.
The invention was developed in view of the above problem and an object thereof is to provide a method for producing a male terminal fitting and a male terminal fitting having an improved operability.
The invention relates to a method for forming a tab of a terminal fitting so that edges at the tip of the tab are rounded or smoothed. Thus, the edges will not damage wall surfaces of a cavity in a connector during insertion of the terminal fitting into the cavity. Similarly, the edges will not damage a rubber plug as the male terminal fitting is introduced into a through hole of the plug.
The terminal fitting is a male terminal fitting that has a tab with a long narrow base and a tapered tip at the leading end of the base. The method comprises longitudinally folding substantially flat sections continuously provided along a widthwise direction of a metallic plate. The method then comprises providing a mold with a pressing recess that has a closed back end. The method further includes bringing the mold closer to the tab from the front of the tab and inserting the leading end of the tab into the pressing recess and striking the tip with back wall at the closed back of the pressing recess. Thus, edges of the tip are smashed or deformed and rounded.
Accordingly, the edges will not are damage wall surfaces of a cavity of a connector during insertion of the male terminal fitting into the cavity. Similarly, the edges will not damage a rubber plug as the male terminal fitting is introduced into a through hole of the plug.
Leading ends of the substantially flat sections preferably are cut to be arcuate and narrowed in plan view The method then may comprise substantially aligning the cut surfaces at the leading ends of the substantially flat sections. Accordingly, the edges are reduced and rounded better as compared to the trapezoidal tip of the prior art.
Preferably, the tip and at least part of the base of the tab are inserted closely into the pressing recess when the mold is struck against the tab. In particular, the mold is brought closer to the tab along the longitudinal direction of the tab. Thus, the inner circumferential walls of the pressing recess support the leading end of the tab. Accordingly, the pressing forces of the mold will not cause the tab to undergo a bending deformation.
Most preferably, the flat sections are formed to have slanted surfaces that are slanted in thickness direction of the metal plate.
The invention also is directed to a male terminal fitting that has a tab with a long narrow base and a tapered tip at the leading end of the base. The tab is formed by longitudinally folding substantially flat sections of a metallic plate continuously along a widthwise direction. The tip is arcuate in plan view, and hence narrows toward the leading end. Accordingly, the edges are reduced and rounded better as compared to the prior art trapezoidal tip.
The tip preferably is formed by pressing. Additionally, the arcuate cut surfaces at the leading ends of the respective flat sections preferably are substantially aligned.
Most preferably, the flat sections have slanted surfaces that are slanted in thickness direction of the metal plate.
These and other objects, features and advantages of the invention will become more apparent upon reading the following detailed description and accompanying drawings. Even though embodiments are described separately, single features thereof may be combined to additional embodiments.